THEN AND NOW: Twins Greg and Alexa Ammon, pictured here this week, tell of their family’s scandal-scarred life in a new documentary. Photo: Joan Jedell

THEN AND NOW: Twins Greg and Alexa Ammon, pictured with parents Ted and Generosa Ammon, tell of their family’s scandal-scarred life in a new documentary. (People Magazine)

THEN AND NOW: Twins Greg and Alexa Ammon, pictured with parents Ted and Generosa Ammon, tell of their family’s scandal-scarred life in a new documentary. (People Magazine)

GUILTY AFTERMATH: Danny Pelosi and paramour Generosa Ammon, whose husband he killed a year earlier, together in England in 2002. Inset: Twins Greg and Alexa Ammon are seen with parents Ted and Generosa Ammon (Glenn Harvey Pictures)

They were children of privilege who became collateral damage in the murder that rocked the Hamptons 11 years ago — and now, as adults, the tragic Ammon twins are finally revealing their torment.

Greg and Alexa Ammon, the adopted children of slain financier Ted Ammon, have emerged to tell their story, from learning of the grisly crime to searching for their long-lost biological family.

In their revealing new documentary, they provide an intimate look at their lives, from their early childhood at a Dickensian orphanage in Kiev to the day they found out that Danny Pelosi, whom they adored as a fun-loving stepdad, had killed their father.

The murder by Pelosi, a charming but evil electrician who had been having a sordid affair with Ammon’s estranged wife, Generosa, and its years-long aftermath played out in the pages of The Post, television newsmagazines and a made-for-TV movie.

Last Friday, the twins stepped out on the red carpet at the Hamptons International Film Festival to promote the movie — their first public appearance since 2004, when they told a judge that Pelosi should spend the rest of his life in prison.

“We loved the guy who killed our father,” explains Greg, now 22, in the film that he directed.

Ammon, 52, was found naked and bludgeoned to death in the bedroom of his English-style country house on Oct. 22, 2001, while in the midst of a bitter divorce and custody battle.

He had been tortured with a stun gun during the beating.

Copies of The Post appear throughout the film, “59 Middle Lane,’’ as milestone markers.

“What was I going to do, not look at it?” he asks his sister in one exchange on all the coverage.

“You wake up in the morning, get dressed like a normal day and Aunt Sandi comes in, and Aunt Sandi, of course, lives in Alabama, and we are like why are you here,” recalls Greg of being told that their father was dead.

Ammons’ divorce from Generosa was just days away from being finalized at the time. Had it gone through, she would have been frozen out of his fortune.

In the 91-minute film, the twins, now living thousands of miles apart, reunite to make sense of their lives by revisiting the family mansion at 59 Middle Lane in East Hampton and later travel to their native Ukraine.

“I feel like I want to put an end to all the horrible things that happened,” Greg says in the film.

At the Long Island home, they explore their favorite hiding spot — an alcove that housed the security system that was mysteriously disabled the night of the murder.

“Bringing the film back to the Hamptons and premiering it in the same theater I went to as a kid will be very emotional and, hopefully, therapeutic,” Greg told The East Hampton Press before the opening.

The film is scheduled to be shown again at Jazz at Lincoln Center, where Ammon had been a longtime supporter.

Coming to terms with the loss of their family is the central theme of the documentary.

For a time, Pelosi and Generosa were shacking up at The Stanhope hotel on Fifth Avenue, while they renovated a $9 million townhouse on East 87th Street.

The kids, then about 10 years old, frequently visited them there.

They recall their mom, still fighting the divorce, making them steal documents from their father if they wanted to watch TV.

Just months after the murder, Pelosi divorced his wife. The very next day, he married Generosa, who inherited much of Ammon’s $80 million fortune because their divorce was never finalized.

They lived in Ammon’s mansion and later in Pelosi’s modest Long Island home as they ducked the press and any others, including investigators, who might have been looking for them.

All the while, friends and family of Ammon were shocked that cops failed to make a arrest.

Life, however, was far from good for Generosa. She was diagnosed with breast cancer and died in August 2003.

“I remember Mom, but all I remember are the bad things,” Greg confesses in his film.

The twins were left in the care of a nanny until their aunt, Ammon’s sister Sandi, won custody and raised them in Huntsville, Ala. All the while, Pelosi fought in court for a share of the Ammon fortune.

It wasn’t until March, 24, 2004, that Pelosi was finally arrested. He maintained his innocence but was convicted of murder and won’t be eligible for parole until 2031.

Pelosi, now 52, still claims Generosa hired a hit man to kill Ammon, an allegation that the twins don’t address in the film.

But Greg and Alexa never doubt Pelosi was the murderer.

“I hope you suffer and go through just as much as my sister and I have,” a teary, then-14-year-old Greg told a Riverhead courtroom at Pelosi’s sentencing.

“I just hope God can forgive you, because I certainly won’t.”

He added, “I was devastated that the man I trusted and loved killed my own father. It’s hard to realize that the person you loved stabbed you in the back and ruined the rest of your life . . . You are a sick man, and I regret every single time I said I loved you.”

Likewise, Alexa couldn’t believe the betrayal by Pelosi.

“Mr. Pelosi might have had a nice time for the past couple of years spending my parents’ money, but that is over now, and I hope he rots away in prison because he deserves nothing better,” she said at the time.

The twins still own the home at 59 Middle Lane. But their lifestyle is somewhat more modest than the one they had as kids, when they flew around the world with their adoring dad in private jets.

Their inheritance was $1 million each after taxes, attorneys’ fees and funds lost to Pelosi’s squandering.

The documentary takes a twist when the siblings travel to Ukraine to explore their roots in Kiev and the orphanage where they were adopted as malnourished kids.

They learned there that their mother was an alcoholic prostitute and that their conception was the result of a one-night tryst with a soldier.

But they found two half-siblings, a brother and a sister.

The mother, who had six other children, died in 2004.

“Ultimately, that story in the Ukraine is very similar to our story in America,” Greg told The East Hampton Press. “When I’m speaking about our birth mother, I’m speaking about my adopted mother, too. I try to tell both of their stories.

“I didn’t want to tell the audience directly how I felt. It was important for them to come their own conclusions.”